জাভাস্ক্রিপ্ট ইভেন্ট

<button onclick="sayHello()">Click Me</button>
<script>
  function sayHello() {
    alert("Hello from inline event!");
  }
</script>

<button id="btn">Click</button>

<script>
  document.getElementById("btn").onclick = function () {
    alert("Clicked!");
  };
</script>

const btn = document.getElementById("btn");

btn.addEventListener("click", function () {
  alert("Event using addEventListener");
});

<div id="box" style="width:100px;height:100px;background:red;"></div>

<script>
  const box = document.getElementById("box");
                                    
  box.addEventListener("mouseover", () => {
    box.style.background = "blue";
  });
                                    
  box.addEventListener("mouseout", () => {
    box.style.background = "red";
  });
</script>

document.addEventListener("keydown", function (e) {
  console.log("Key pressed:", e.key);
});

<form id="myForm">
  <input type="text" name="username" />
  <button type="submit">Submit</button>
</form>
                                  
<script>
  const form = document.getElementById("myForm");
                                  
  form.addEventListener("submit", function (e) {
    e.preventDefault(); // আসল ফর্ম সাবমিশন প্রতিরোধ করে
    alert("Form submitted via JavaScript!");
  });
</script>

document.addEventListener("click", function (event) {
  console.log(event.type);   // click
  console.log(event.target); // যে এলিমেন্টে ক্লিক করা হয়েছে
});

function greet() {
  alert("Hello!");
}
                                  
btn.addEventListener("click", greet);
                                  
// পরে...
btn.removeEventListener("click", greet);